Chapter Inorganic)

4.1 Sketch a graph to show the variation of each of the following properties with proton number for the Group IV elements of the Periodic Table. (a) Atomic radius (b) First ionisation energy (c) Electronegativity (d) Melting point (e) Electrical conductivity 4.2 Germanium is obtained by heating the germanite ore with hydrogen chloride to produce germanium chloride,which is then hydrolysed to germanium oxide.Subsequent reduction of germanium oxide produces germanium.When 1.00 g of ther germanite is used for this process,it produces 0.177 g of chloride that contain 33.9% by mass of germanium.Calculate (a) the empirical formula of the chloride (b) the oxidation number of germanium in the chloride (c) the percentage of germanium in the germanite sample 4.3 Complete the table below with regards to the properties of the group 14 chlorides. CCI4

SiCl4

PbCl₂

Physical state/298 K Conductivity in the liquid state Reaction with water Type of bonding Molecular structure

4.4 A group 14 element forms a divalent ion that decolourises aquaeous acidified potassium manganate(VII) (a) Name the element (b) Write the equation for the reaction between the ion and acidified manganate(VII) ion. 4.5 (a) Describe the differences between a graphite and a diamond in terms of structure and physical properties (b) Give one large-scale use of diamond and graphite 4.6 Silicon tetrachloride undergoes hydrolysis with water,but carbon tetrachloride does not.Explain why it is so. 4.7 Discuss (a) the relative stability of the +2 and +4 oxidation state of the Group 14 elements (b) the volatility,the thermal stability and hydrolysis of the Group IV tetrachlorides 4.8 Many soils rich in silicate clays show signs of cracks in their structure during dry seasons. (a) Identify the type of clay that is liable to develop such cracks. (b) Draw a simple diagram to show its layer structure (c) Suggest how these cracks appear when the wet soil dries out a)